Papain/HA-Phe自组装复合纳米粒子及乳化性能

Self-assembled Papain / HA-Phe Composite Nanoparticles and Emulsification Properties

用L-苯丙氨酸乙酯(L-Phe)改性透明质酸(HA)双亲性生物大分子(HA-Phe)负载生物活性分子木瓜蛋白酶(papain),HA-Phe和Papain通过静电、氢键和疏水相互作用自组装形成生物基Papain/HA-Phe复合纳米粒子.用动态光散射(DLS)和透射电镜(TEM)对复合纳米粒子的尺寸和形貌进行表征.结果显示,形成的复合纳米粒子为球形结构,粒径约308 nm.以此复合纳米粒子为颗粒乳化剂稳定白油,形成水包油型Pickering乳液.乳液的扫描电镜(SEM)显示,复合纳米粒子吸附在油水界面,形成复合纳米粒子的吸附层以稳定乳液.详细研究了pH和盐浓度对复合纳米粒子性质和复合纳米粒子乳化性能的影响.结果表明,随着pH增加,复合纳米粒子在油滴表面的吸附数目减少,乳化性能降低;随着盐浓度增加,复合纳米粒子的形变能力增强,乳化性能提高.进一步研究了乳液中木瓜蛋白酶的活性及美白效果.研究表明,制备的乳液保留了一定的活性,且具有一定的美白效果.

Novel bio-based composite nanoparticles （Papain/HA-Phe） were prepared through the electrostatic interaction,hydrogen bonding and hydrophobic interaction between papain and amphiphilic L-phenylalanine ethyl ester-modified hyaluronic acid （HA-Phe）. The sizes and morphologies of the composite nanoparticles were characterized by dynamic light scattering （DLS） and transmission electron microscopy （TEM）. The results showed that the composite nanoparticles had uniformly spherical structure with a size of 308 nm. The composite nanoparticles were used as particulate emulsifiers to stabilize white oil, forming oil-in-water Pickering emulsions. Scanning electron microscopy （SEM） characterization of emulsions demonstrated that the composite nanoparticles were adsorbed at the oil-water interface and formed the adsorption layer of composite nanoparticles to stabilize emulsions. The influences of pH values and salt on the properties of composite nanoparticles and emulsifying performances were carefully investigated. The results showed that the adsorption number of composite nanoparticles at surface of oil drops decreased and emulsifying performances of composite nanoparticles decreased with increasing pH value; the deformation degree of composite nanoparticles gradually increased and emulsifying performances increased with increasing salt concentrations. The bioactivity and inhibitory activity against tyrosinase of papain in emulsions were further investigated. The studies showed that the emulsions retained the majority of bioactivity and some inhibitory activity against tyrosinase.